The control of a complex industrial process, such as a chemical refinery or central electric power generating station, is a complex endeavor which places high demands for information processing on equipment and operators. Particularly with respect to nuclear power plants, the control of the plant and its processes must not only satisfy objectives arising from economic optimization, but also must satisfy safety objectives more stringent than those faced by virtually any other industry.
In the nuclear power industry, recent developments in instrumentation and control engineering have been directed toward the integration and presentation of information to the operator in the plant central control room, in a manner that gives the operator a higher level of understanding of the condition of the plant or of particular systems and processes. Particularly under the stress of an abnormal plant occurrence, it is not an easy task for the operator to infer the nature of the problem and decide upon the most appropriate mitigating action, in response to stimulus overload from alarms and other displays concerning individual parameters and individual components.
Considerable progress has been made with respect to integrating parameter and component signals into more useful indicator and monitor displays for the operator, as described, for example, in International Pat. application Ser. No. PCT/US89/04899 filed Nov. 2, 1989 for "Advanced Nuclear Plant Control Complex", the disclosure of which is hereby incorporated by reference. Despite improvements in monitoring and display, the development of an easy-to-use, integrated controller interface has not kept pace. In particular, although the operator has available to him improved indicators, alarms, and other monitoring interfaces, the manner in which the operator must divide his attention between the control panel, at which action is taken to actuate components and the indicator panel, where the results of control action are observed, has not improved commensurately.
One example of a process controller representing the recent state of the art, is shown in FIG. 1, which depicts a man-machine interface for the process control associated with the operation of the pressurizer system in a pressurized water nuclear power plant. The interface is premised on the understanding that the behavior of the pressurizer system can be influenced by controlling either on pressure in the pressurizer, or by the liquid level in the pressurizer. Thus, pressure control, level control, and the signal inputs for the system are controlled from the common man-machine interface device shown in FIG. 1.
The pressure and level control functionality associated with the device of FIG. 1, are each a master controller that sends signals to subgroup controls. For example, the pressurizer level controller controls level by sending signals to one or both of the charging pumps and letdown valves. Such action also affects the pressure in the pressurizer. If, however, the operator wants to control the charging pumps or letdown valves individually, the necessary controls are located on a different man-machine interface device. Looked at more generally, the prior art as represented by FIG. 1, provides a process controller device by which the operator can establish a setpoint or specify a demand for one or more process parameters in a given system. If the parameter is responsive to the operation of only one component, then control of such parameter is tantamount to the control of the component. Where, however, a plurality of components are available to adjust the parameter, the process controller acts as a master controller over this subgroup of components, but the operator cannot adjust the subgroup components individually, without going to a separate control device.